(D) If You are connected to Internet and can surf
Check your IP Static or Dynamichttp://checkip.dyndns.com/
Then enter it in Browser address bar.
Then a window will open to access the router.
(E) Reset the modem with power on for 20 to 30
seconds . Factory Defaults are Restored.
If the ISP has changed IP/Modem UserID/PW
we cannot do anything.